Strategy. Under normal circumstances, the fund invests at least 80% of its assets in investment grade Massachusetts municipal securities or other investments with similar economic characteristics. Massachusetts municipal securities are securities the interest on which is exempt from regular federal income tax and Massachusetts state personal income taxes. The funds 80% policy may not be changed without a shareholder vote. Interest on Massachusetts municipal securities may be subject to the federal alternative minimum tax. Massachusetts municipal securities include debt obligations issued by the Commonwealth of Massachusetts and its political subdivisions, agencies and public authorities, certain other governmental issuers (such as Puerto Rico, the U.S. Virgin Islands and Guam) and other qualifying issuers. These securities include participation or other interests in municipal … Show more… Under normal circumstances, the fund invests at least 80% of its assets in investment grade Massachusetts municipal securities or other investments with similar economic characteristics. Massachusetts municipal securities are securities the interest on which is exempt from regular federal income tax and Massachusetts state personal income taxes. The funds 80% policy may not be changed without a shareholder vote. Interest on Massachusetts municipal securities may be subject to the federal alternative minimum tax. Massachusetts municipal securities include debt obligations issued by the Commonwealth of Massachusetts and its political subdivisions, agencies and public authorities, certain other governmental issuers (such as Puerto Rico, the U.S. Virgin Islands and Guam) and other qualifying issuers. These securities include participation or other interests in municipal securities issued or backed by banks, insurance companies and other financial institutions. Some municipal securities, such as general obligation issues, are backed by the issuers taxing authority, while other municipal securities, such as revenue issues, are backed only by revenues from certain facilities or other sources and not by the issuer itself. The fund focuses on investment grade bonds (that is, securities rated in the Baa/BBB categories or above or, if unrated or deemed to be unrated by the subadviser, determined to be of comparable credit quality by the subadviser) but may invest up to 20% of its assets in below investment grade bonds (commonly known as high yield or junk bonds). The fund may invest in securities of any maturity. The fund focuses primarily on intermediate-term and long-term municipal securities, and will normally invest in securities which have remaining maturities at the time of purchase from one to more than thirty years. The fund may also invest in securities of other open-end or closed-end investment companies, including exchange-traded funds (ETFs), that invest primarily in municipal securities. Instead of, and/or in addition to, investing directly in particular securities, the fund may use instruments such as derivatives, including options, futures contracts and inverse floating rate instruments issued in tender option bond transactions, and other synthetic instruments that are intended to provide economic exposure to the securities or the issuer or to be used as a hedging technique. The fund may use one or more types of these instruments without limit, except that these instruments are taken into account when determining compliance with the funds 80% policy. For additional information regarding derivatives, see More on the funds investment strategies, investments and risksDerivatives in the Prospectus. The fund may also engage in a variety of transactions using derivatives in order to change the investment characteristics of its portfolio (such as shortening or lengthening duration) and for other purposes. The fund may leverage its assets by investing proceeds received through tender option bond transactions, which is considered a form of borrowing. See More on the funds investment strategies, investments and risksTender option bonds in the Prospectus. The fund is classified as non-diversified, which means it may invest a larger percentage of its assets in a smaller number of issuers than a diversified fund. Show less